Herbalife (HLF) shares jumped 7% in early morning trading after Dan Loeb's hedge fund disclosed an 8.9 million share purchase of the weight loss supplement company. His hedge fund, Third Point, now owns an 8.2% stake in Herbalife. Herbalife's shares have been extremely sensitive to comments made by hedge fund managers. Two weeks ago, noted short seller Bill Ackman called the company a "pyramid scheme," sending shares plummeting 12%. Herbalife uses